The present invention is a surgical device assembly and method. More particularly, it is an endolumenal prosthesis assembly and method for implanting an endolumenal prosthesis within a body lumen. Still more particularly, the invention is an endolumenal prosthesis delivery assembly with an endolumenal prosthesis releasably coupled to a first delivery member that tracks over a second delivery member which has an anchor that secures the second delivery member within the body lumen distally of the desired location for delivering the prosthesis.
A wide range of medical treatments have been previously developed using xe2x80x9cendolumenal prostheses,xe2x80x9d which terms are herein intended to mean medical devices that are adapted to be implanted within a body lumen. Examples of lumens in which endolumenal prostheses may be implanted include, without limitation: blood vessels, including arteries and veins, and such as for example those located within the coronary, mesentery, peripheral, or cerebral vasculature; the gastrointestinal tract; biliary ducts; the urethra; and fallopian tubes.
Various different types of endolumenal prosthesis have also been developed, each providing a uniquely beneficial structure intended to mechanically couple to the specifically targeted lumenal wall. For example, various stents, grafts, and combination stent-graft prostheses have been previously disclosed for implantation within body lumens in order to provide artificial radial support to the lumenal wall tissue while maintaining lumenal patency through the supported region. One more frequently disclosed arterial xe2x80x9cstentingxe2x80x9d procedure involves implanting a stent in an artery in order to provide radial support to the vessel to thereby prevent abrupt closure subsequent to recanalization of stenosed regions of the artery, such as by balloon angioplasty or atherectomy (mechanical dilation of stenosed vessel by radial balloon expansion or by direct removal of stenotic plaque, respectively).
Conventional Stent Designs
Stents are designed to provide radial support to the vessel wall and also forms a prosthesis passageway or stent lumen extending centrally through the stent in order to provide a conduit for flow through the stented region. Moreover, a wide variety of stent designs have been previously disclosed that differ in the aspect of their structural design. In general, most of these various stent structures include a network of integrated support members having a geometry such that the networked design defines a longitudinal passageway. The structural integrity of the integrated support members provides radial rigidity against physiological collapsible forces at the vessel wall, whereas the longitudinal passageway through the prosthesis allows for flow through the stented region.
Various examples of previously disclosed stent structures include, without limitation: wire mesh; coiled wire; slotted tubes; and connected rings. More detailed examples of these types of stents are also variously disclosed in the following references: U.S. Pat. No. 4,580,568 issued to Gianturco; U.S. Pat. No. 4,655,771 issued to Wallsten; U.S. Pat. No. 4,733,665 issued to Palmaz; U.S. Pat. No. 4,739,762 issued to Palmaz; U.S. Pat. No. 4,776,337 issued to Palmaz; U.S. Pat. No. 4,830,003 issued to Wolff et al.; U.S. Pat. No. 5,571,172 issued to Chin; U.S. Pat. No. 4,913,141 to Hillstead; U.S. Pat. No. 4,969,458 issued to Wiktor; U.S. Pat. No. 5,019,090 issued to Pinchuk; and U.S. Pat. No. 5,292,331 issued to Boneau; U.S. Pat. No. 5,817,152 issued to Birdsall. The disclosures of these references are herein incorporated in their entirety by reference thereto.
Conventional Stent Delivery Assemblies and Methods
Various stent delivery assemblies and methods have also been disclosed which are adapted to deliver particular stents within desired locations of specific body lumens or lumens and to thereafter implant the stents at their respectively desired locations. In general, stents are adapted to be delivered to the desired location by engaging the stent in a radially collapsed condition to a coupler on a delivery member or catheter which is adapted to be delivered to the desired location via known access procedures, such as for example via known translumenal procedures. In a further more detailed example adapted for percutaneous translumenal catheterization procedures, the delivery member is a catheter which is adapted to track over a second delivery member, such as for example a guidewire, which is specifically adapted to subselect a percutaneous translumenal path to the desired location and provide a rail for the first delivery member to follow.
Once delivered and positioned at the desired location for implantation, the stent is then adjusted to a radially expanded condition which is adapted to radially engage the interior surface of the lumenal wall tissue, such as a vessel wall in an arterial stenting procedure. Further to this generally applicable stent delivery method just described, various stent designs have also been disclosed which differ in the aspect of their structure which allows the expansion from the radially collapsed condition to the radially expanded condition. Examples of different stent structures which are adapted according to these varied modes of delivery include, without limitation: xe2x80x9cself-expandingxe2x80x9d stents, which generally expand under their own force once delivered to the desired stenting site; and xe2x80x9cballoon expandablexe2x80x9d stents, which generally expand under mechanical strain from an inflating balloon at the stenting site.
Further to the xe2x80x9cself-expandingxe2x80x9d stent variation just described, one more detailed example of this type of stent is adjustable from the radially collapsed condition to the radially expanded condition by removing a radial constraining member once delivered to the stenting site. This type of self-expanding stent is adapted to recover from an elastically deformed state, when radially confined by the constraining member in the radially collapsed condition, to a resting or recovered state in the radially expanded condition, when radially unconstrained. Further detailed examples of known constraining members for use in delivery systems for such known self-expanding stents include, without limitation, radially confining sheaths, releasable tethers, and other securing devices which are releasably coupled to the stent wall when in the radially collapsed condition. Still further, another more specific example of a previously disclosed xe2x80x9cself-expandingxe2x80x9d stent is one which is formed from a shape-memory alloy and is adjustable from the radially collapsed condition to the radially expanded condition by heating the stent once delivered to the stenting site, thereby inducing a heat-memory recovery of the material in the stent wall to the radially expanded condition. One drawback of self-expanding stent assemblies is the difficulty of accurate positioning. Specifically, the stent tends to advance or xe2x80x9cpopxe2x80x9d forward when released. For example, a self-expanding stent assembly utilizing a radially confining sheath will typically include an inner member to hold the stent in position while the outer sheath is removed. However, it has been observed that when the sheath is withdrawn, the stent tends to advance in unpredictable fashion.
Further to the xe2x80x9cballoon expandablexe2x80x9d stent variation previously described, according to one more detailed example a stent is crimped or otherwise held in the radially collapsed condition over an exterior surface of a balloon on the distal end of a balloon catheter. The balloon catheter is adapted to track over a guidewire to the desired location for stent implantation. Inflating the balloon at the desired location adjusts the stent to the radially expanded condition which is adapted to engage the body lumen or lumen wall. Subsequent deflation of the balloon thereby leaves the stent implanted within the lumen. Further detailed examples of previously known xe2x80x9cballoon expandablexe2x80x9d stents and related delivery assemblies include, without limitation: assemblies which provide stents xe2x80x9cpre-loadedxe2x80x9d over a balloon catheter; and assemblies which provide a stent to a user separately from the balloon delivery assembly, allowing the user to crimp the stent onto the balloon immediately prior to delivery in vivo.
Further more specific examples of specific stent designs which are adapted for the various modes of delivery just described above are disclosed variously throughout the following references, the disclosures of which have been previously incorporated by reference thereto: U.S. Pat. No. 4,580,568 issued to Gianturco; U.S. Pat. No. 5,571,172 issued to Chin; U.S. Pat. No. 4,733,665 issued to Palmaz; U.S. Pat. No. 4,739,762 issued to Palmaz; U.S. Pat. No. 4,776,337 issued to Palmaz; U.S. Pat. No. 4,830,003 issued to Wolff et al.; U.S. Pat. No. 4,913,141 issued to Hillstead; U.S. Pat. No. 4,969,458 issued to Wiktor; U.S. Pat. No. 5,019,090 issued to Pinchuk; and U.S. Pat. No. 5,292,331 issued to Boneau; U.S. Pat. No. 5,817,152 issued to Birdsall.
Complex Stent Delivery Systems
In addition to the specifically designed stents and delivery assemblies previously described above, other detailed assemblies and methods have also been disclosed which are specifically designed to overcome the particular anatomic challenges associated with specific stenting procedures.
For example, at least one other stent delivery assembly and method has been disclosed which is specifically adapted for delivering and positioning a stent in the ductus arteriosis. In particular, a double balloon catheter having a first stent delivery balloon located proximal to a second distally located distal end balloon is adapted to be engaged securely within the ductus arteriosis of an infant. After catheter delivery to the delivery site, the distal end balloon is first inflated into a spherical configuration within the ductus arteriosis, then the catheter is withdrawn until the distal balloon abuts the opening. When the abutment is realized, the stent balloon, which carries a stent, is selectively inflated while maintaining the distal end balloon in an inflated condition. This balloon inflation expands and subsequently embeds the stent at the target site in the ductus arteriosis.
In another example, at least one other stent delivery assembly and method is also known which is intended to specifically implant a stent at a desired location in the urethra, and more particularly in order to prevent urethral strictures following a surgical procedure. By reference to one known design according to this application, an elongated cylindrical stent includes a contractible locating member attached at one end and a retrieving string attached at the other end. The contractible member is fastened to the elongated stent body by two flexible strings and is maintained in a radially contracted condition by a cylindrical pusher prior to insertion into the bladder through the narrow urethra lumen. After delivery to the urethra using a pusher along a guidewire, the contractible member is deployed to a radially expandable conformation by removal of the cylindrical pusher, thus lodging the contractible member at the target site.
More detailed examples of stent delivery assemblies and methods of the types just described for use in the ductus arteriosis and urethra are disclosed in the following references: U.S. Pat. No. 5,322,501 issued to Mahmud-Durrani and U.S. Pat. No. 5,261,878 issued to Galindo. The disclosures of these references are herein incorporated in their entirety by reference thereto.
Still further, other stent delivery assemblies have been disclosed which are intended for use in stenting a stenosed region of a vessel in addition to dilating the stenosis, and are herein referred to as xe2x80x9cBalloon Dilatation/Stent Deliveryxe2x80x9d assemblies.
One example of a previously disclosed balloon dilatation/stent delivery assembly comprises an integrated catheter system including a stent catheter and an xe2x80x9cover-the-wirexe2x80x9d balloon angioplasty catheter. The stent catheter contains a radially expandable stent which is adapted to be held in place over the partially inflated balloon of the balloon catheter upon delivery to the site of lesion. The balloon catheter with the inflatable balloon is positioned at the catheter""s distal end which is initially inflated at low pressure to engage the vessel wall and thus dilate the vessel. The stent catheter contains an elongated passageway with a tapered distal end through which the balloon catheter can be slideably moved and a stent which is radially confined within a stent containment cavity which can be adapted to slide over the partially inflated balloon using a guidewire. This same guidewire is used to advance the stent to the site of lesion. The withdrawing of the containment member upon stent delivery to the target site results in a radially expandable deployment of the stent from the containment cavity. The balloon is then inflated radially outward so as to embed the stent within the vessel wall.
Another example of a known balloon dilatation/stent delivery assembly embodies an assembly comprising an a xe2x80x9cover-the-wirexe2x80x9d balloon angioplasty catheter in combination with a radially expandable stent. The stent delivery guide catheter contains a dilatation catheter with an inflatable balloon which first dilates the stenosis. The balloon is then deflated and withdrawn back into the delivery catheter until it spans the stent and a bladder located within the delivery catheter. The bladder is then inflated by a pressure source thus compressing the stent radially inward to become deposited on the balloon catheter. The dilatation catheter which is now carrying the stent, is once again advanced to the site of lesion in the coronary artery. The balloon is inflated and the stent is implanted into the stenosis.
In another example of a balloon dilatation/stent delivery assembly, a coil shaped stent is initially located proximal to a balloon on a balloon tipped catheter. The balloon tipped catheter is first advanced to the site of the plaque and the balloon is expanded to compress the plaque against the vessel wall. The stent is then advanced along the catheter body onto the balloon of the balloon tipped catheter by a catheter jacket located proximal to the stent. After the balloon is expanded and subsequently withdrawn, the stent remains in situ to reinforce the arterial wall.
According to still a further example of a previously disclosed balloon dilatation/stent delivery assembly, a stent delivery catheter contains two balloons situated near the distal end of the catheter and is introduced into the patient and navigated to the target site by common use of a guidewire. The catheter has bulges located at one end of and within each balloon. A compressed stent is disposed around one balloon and between the bulges. The use of this bulge design allows the stent to be fixed securely about the balloon thus eliminating the need for any stent containment device. The more distally located balloon may be first inflated to dilate the occluded vessel near the stent implantation site.
More specific stent delivery devices and methods according to the above referenced examples may be found variously among the disclosures of the following references: U.S. Pat. No. 5,639,274 issued to Fischell et al.; U.S. Pat. No. 5,222,969 issued to Gillis; U.S. Pat. No. 5,632,760 issued to Sheiban et al.; and U.S. Pat. No. 5,628,754 issued to Shevlin et al. The disclosures of these references are herein incorporated in their entirety by reference thereto.
Notwithstanding the features and intended applications of the various balloon dilatation/stent delivery assemblies just described, many stent delivery assemblies of the xe2x80x9cballoon expandablexe2x80x9d type are also known to have sufficiently large profiles such that tight stenoses may be difficult to cross initially prior to dilatation stenting. One particular complication which has been observed due to this crossing profile challenge is known as xe2x80x9cguide catheter back-out,xe2x80x9d which is generally described as follows.
Guiding catheters are devices which generally provide a lumenal conduit through which the stent delivery assembly is percutaneously delivered into an ostium of a desired vessel tree in which the stent is to be implanted. In addition, guiding catheters are intended to provide xe2x80x9cback-upxe2x80x9d support to allow the stent delivery assembly to be pushed through severe bends or against and through a tight lesion. However, a guiding catheter""s support can reach its limit upon encountering a sufficiently tight stenosis with the stent assembly. In such a circumstance, the guiding catheter may unseat from the ostium wherein much of the guiding catheter support and concomitant pushability of the stent assembly is lost. In some circumstances, this xe2x80x9cback-outxe2x80x9d phenomenon may be overcome such as by xe2x80x9cdeep-seatingxe2x80x9d the guiding catheter within the ostium, or by replacing the whole system to include a guiding catheter with a different shape or stiffer construction. In other more severe circumstances of tight lesions, however, predilatation of the stenosis with a separate balloon may be required prior to stent delivery.
Accordingly, there remains a need for a stent delivery assembly which effectively prevents guiding catheter back-out when attempting to advance a stent delivery assembly through severe bends or tight lesions.
Another example of a specific stenting procedure which presents particular challenges to conventional stents and stent delivery assemblies includes stenting of bifurcation regions of body lumens. In particular, complications and challenges are known to arise from the use of conventional assemblies and methods in bifurcation regions wherein the desired location for stent implantation is either (a) at or closely adjacent to the bifurcation region; or (b) in a branch vessel distally beyond the bifurcation region.
For example, some bifurcation regions present anatomy which is very difficult to track using conventional xe2x80x9cguidewire trackingxe2x80x9d delivery assemblies and methods. In one more particular example, a side-branch lumen extends distally from their respective main vessels at drastic xe2x80x9ctake-offxe2x80x9d angles. In such drastic circumstances, even highly trackable and sub-selective guidewires are difficult to position within such take-offs. However, even in less drastic circumstances where the guidewire is positioned within the side-branch, conventional stents and stent delivery members have been observed to either fail while tracking over the guidewire through such bends or to follow the guidewire only after significant effort.
Moreover, largely due to the presence of the prosthesis in a collapsed and compacted condition during delivery, many stent delivery assemblies are known to be stiffer than many other interventional devices, such as for example when compared with simple balloon angioplasty catheters. Therefore, it has been observed that such stiffness may further complicate the tracking over guidewires through such tortuosities. Accordingly, observed complications in attempting stent delivery in side-branches extending from bifurcations include: prolapsing a guidewire out of the side-branch and into the main lumen while advancing the stent delivery assembly; and guidewire contact or xe2x80x9chang-upxe2x80x9d against the nape of the bifurcation which may increase risk of intimal wall damage in severe cases. Also, the complications which may be associated with wall trauma as just described for some bifurcation procedures may also occur in procedures attempting stent delivery beyond severe bends, such as for example beyond bends of greater than thirty degrees, and also for example beyond multiple sequential bends in a given lumen.
In one known method for delivering conventional stents to bifurcations, a side-branch is first stented, after which a second stent is placed within the main vessel which may include a second side-branch. Another known bifurcation stenting method includes first stenting the main vessel and then advancing a second stent through the interior passageway of the main vessel stent and into the side-branch where it is then implanted. These methods, however, are believed to present some incumbent risks, such as for example: sub-optimal results at the side-branch ostium; or xe2x80x9cjailingxe2x80x9d of the side-branch lumen with a main vessel stent, respectively.
Due to the observed challenges of using conventional stent delivery assemblies and methods for bifurcation stenting procedures, more specifically designed stents and delivery systems have been disclosed which are intended for placement at bifurcation regions. One example of a known xe2x80x9cbifurcationxe2x80x9d stent and related delivery system includes a Y-shaped stent which is adapted to engage both branches of the bifurcating vessel simultaneously using a corresponding xe2x80x9cYxe2x80x9d-shaped delivery assembly with bifurcating balloons. The Y-shaped expandable stent delivery system is intended to avoid damage to the bifurcation region due to sequential positioning of multiple stents. Additional more specific stents, stent delivery devices, and related methods for stenting bifurcations are disclosed in the following references: U.S. Pat. No. 4,994,071 issued to MacGregor and U.S. Pat. No. 5,669,924 issued to Shaknovich. The disclosures of these references are herein incorporated in their entirety by reference thereto.
There is still a need for an endolumenal prosthesis delivery assembly and method for safely and effectively positioning an endolumenal prosthesis within a desired location in a body lumen that is located distally of a severely tortuous bend in the lumen.
There is also still a need for an endolumenal prosthesis delivery assembly and method for safely and efficiently implanting an endolumenal prosthesis within a side-branch lumen extending at a significant angle from a bifurcation region of a vessel.
None of the cited references discloses an endolumenal prosthesis delivery assembly and method for delivering an endolumenal prosthesis within a desired location in a body lumen by anchoring one delivery member within a region of the body lumen distally of the desired location so that another delivery member releasably coupled to the endolumenal prosthesis may slideably engage and track over the first delivery member until the prosthesis is positioned at the desired location.
Nor do the cited references disclose an endolumenal prosthesis delivery assembly with an anchor on a delivery member which is adapted to prevent guiding catheter back-out during delivery of the endolumenal prosthesis with another delivery member to the desired location for implantation.
Moreover, none of the cited references disclose an endolumenal prosthesis delivery assembly with an anchor on a delivery member which is adapted to more precisely and reliably position a self-expanding stent.
The present invention is an endolumenal prosthesis delivery assembly and method for implanting an endolumenal prosthesis within a body lumen in a mammalian body. This assembly and method are believed to be particularly well suited for delivering an endolumenal prosthesis to a desired location for implantation which is located beyond a tortuous in vivo delivery path, such as in a location along a branch vessel beyond a bifurcation region or otherwise along a lumen which is beyond a significant bend or bends. In addition, the assembly and method are further believed to prevent guiding catheter back-out during delivery of the stent delivery assembly through such resistive anatomy. Moreover, the assembly and method are also believed to enable more accurate and reliable placement of a self-expanding stent.
One mode of the present invention is an endolumenal prosthesis delivery assembly that includes an endolumenal prosthesis and first and second coordinating delivery members. The endolumenal prosthesis is a device which is adapted to be implanted within the body lumen. The first delivery member has a proximal end portion and a distal end portion that further includes a prosthesis coupler which is adapted to releasably engage the endolumenal prosthesis. The second delivery member also has a proximal end portion and a distal end portion, and further includes an anchor which is located along its distal end portion. The anchor is adapted to secure the distal end portion of the second delivery member within the body lumen. Further to this mode, the distal end portion of the first delivery member is adapted to slideably engage and track along the distal end portion of the second delivery member such that the endolumenal prosthesis when engaged to the prosthesis coupler may be positioned along the distal end portion of the second delivery member proximally of the anchor.
In one aspect of the endolumenal prosthesis delivery assembly mode of the invention, the anchor is adjustable from a first position, which is adapted to be delivered within the body lumen, to a second position, which is adapted to be secured within the body lumen. In one variation of this aspect, the anchor includes an expandable member which is adjustable with an expansion member from the first position to the second position. Further to this variation, the first position is characterized by a radially collapsed condition that is adapted to be delivered within the body lumen, and the second position is characterized by a radially expanded condition that is adapted to radially engage the body lumen wall to thereby secure the anchor within the body lumen. In still a further variation, the expandable member is an inflatable balloon, and in a further aspect of this variation the balloon is designed to have a compliance which exhibits at least a two-hundred percent elastic expansion when pressurized by a pressurizeable fluid source to a pressure of approximately three to five atmospheres. In again another variation, the expandable member is an expandable cage or basket which mechanically adjusts to the radially expanded condition for anchoring within a vessel lumen.
In another aspect of the endolumenal prosthesis delivery assembly mode of the invention, the second delivery member is a guidewire with a radiopaque distal tip located distally of the anchor and which is steerable within the body lumen by torquing the proximal end portion of the second delivery member. In one variation of this aspect, the anchor is an inflatable balloon and the second delivery member provides an inflation lumen which is formed at least in part by a tubular member which is also torquable and torsionally coupled to the radiopaque distal tip.
In another aspect of the endolumenal prosthesis delivery assembly mode of the invention, the first delivery member includes a lumen which extends between a distal port located distally of the prosthesis and a proximal port located proximally of the prosthesis. The lumen according to this aspect is adapted to slideably engage and track over the distal end portion of the second delivery member at least proximally of the anchor.
In one further variation of this xe2x80x9ctracking lumenxe2x80x9d aspect of the first delivery member, the anchor on the second delivery member is adjustable from a first position, which is adapted to slideably engage the lumen through the proximal port and to advance distally of the distal port to be delivered within the body lumen, to a second position, which is adapted to be secured within the body lumen.
In another variation of the xe2x80x9ctracking lumenxe2x80x9d aspect of the first delivery member, the lumen of the first delivery member has an inner diameter which is smaller than the outer profile of the anchor in the first position. According to this variation, the distal end portion of the second delivery member is adapted to slideably engage the lumen by backloading the second delivery member""s proximal end through the distal port, proximally through the lumen, and out of the proximal port. Further to this variation, the first delivery member""s distal end portion is adapted to advance and track over the distal end portion of the second delivery member proximal of the anchor.
In still a further more detailed design according to the xe2x80x9cbackloadingxe2x80x9d variation just described, the anchor is an inflatable balloon. The second delivery member includes an inflation lumen coupled to the balloon and also a removeable coupler which is adapted to removably engage the second delivery member""s proximal end portion. According to this detailed design, when the removeable coupler is engaged to the second delivery member""s proximal end portion the inflation lumen is adapted to fluidly couple to a pressurizeable fluid source. In an alternative mode of operation, by removing the removeable coupler from the second delivery member""s proximal end portion the second delivery member is adapted to be backloaded through the lumen of the first delivery member.
In another aspect of the endolumenal prosthesis delivery assembly mode of the invention, the endolumenal prosthesis includes an endolumenal stent which forms a stent passageway. The stent is adjustable from a radially collapsed condition with a collapsed outer diameter to a radially expanded condition with an expanded outer diameter. The expanded outer diameter is larger than the collapsed outer diameter and is also adapted to radially engage the body lumen wall. Further to this aspect, the prosthesis coupler includes an expansion member which is adapted to adjust the endolumenal stent from the radially collapsed condition to the radially expanded condition.
In one variation of the endolumenal prosthesis aspect of the assembly, the stent is a balloon expandable stent. According to this variation, the expansion member includes an expandable member which is engaged within the stent passageway and is radially expandable. The radially expandable member is adapted to force the endolumenal stent from the radially collapsed condition to the radially expanded condition.
In another variation of the endolumenal prosthesis aspect of the assembly, the endolumenal stent is a self-expanding stent. According to this stent variation, the expansion member includes a delivery sheath with an inner diameter which approximates the collapsed outer diameter of the endolumenal stent. The sheath is adjustable from a confining position to a releasing position. With the sheath in the confining position, the stent is in the radially collapsed condition and is coaxially contained and compressed against an outward radial bias within the delivery sheath. Alternatively, with the sheath in the releasing position, the stent is released from within the delivery sheath and is allowed to thereby expand to the radially expanded condition. In a further aspect, of this embodiment, the distal end of the second delivery member is anchored just distal of the lumenal site desired for stent placement. The stent assembly is then tracked over the second delivery member until its distal end abuts the anchor of the second delivery member. The sheath is then withdrawn, while pressure is exerted on the stent via an inner member, keeping it in abutting relationship with the anchor.
In still a further variation of the endolumenal prosthesis aspect of the assembly, a graft member is engaged to the endolumenal stent to form a stent-graft prosthesis which is adapted to couple to the first delivery member.
In another aspect of the endolumenal prosthesis delivery assembly mode of the invention, the anchor includes a suction port which is coupled to a suction lumen extending along the second delivery member. The suction lumen is adapted to fluidly couple the suction port to a vacuum source such that the anchor is adapted to be secured to the body lumen wall with suction from the source which is applied at the suction port.
Another mode of the present invention is a method for delivering an endolumenal prosthesis to a desired location within a body lumen that is formed at least in part by a body lumen wall in a mammalian body. This method includes slideably engaging the distal end portion of a first delivery member, which includes a prosthesis coupler removeably engaged with an endolumenal prosthesis, with the distal end portion of a second delivery member. The distal end portion of the second delivery member is positioned within the body lumen and is anchored within the body lumen at an anchoring location that is distal to the desired location. After anchoring the second delivery member""s distal end portion, the first delivery member is slideably advanced along the first delivery member until the endolumenal prosthesis is positioned within the body lumen at the desired location.
In one aspect of the method mode of the invention, the body lumen has a severe bend and the desired location is located along the body lumen distally of the severe bend. In another variation of this aspect the body lumen has two successive bend regions, and the anchoring location is located along the body lumen distally of the two successive bend regions. In still another variation of this aspect, the desired location is located along a side branch lumen extending distally from a bifurcation.
In another aspect of the method mode of the invention, the distal end portion of the second delivery member is anchored at the anchoring location by expanding an expandable member along that distal end portion from a radially collapsed condition to a radially expanded condition which radially engages the body lumen wall at the anchoring location.
In another aspect of the method mode of the invention, the distal end portion of the second delivery member is anchored at the anchoring location by applying suction to the body lumen wall at the anchoring location through a distal suction port located along the second delivery member""s distal end portion distally of the endolumenal prosthesis.
In another aspect of the method mode of the invention, after securing the anchor at the anchoring location and before tracking the distal end portion of the first delivery member over the distal end portion of the second delivery member, the second delivery member""s proximal end portion is pulled by a user to impart tension on the respective distal end portion. According to this tensioning aspect of the method, the second delivery member is stiffened within the anatomy proximally of the anchor and is made taught in order to provide more robust support as a rail over which the first delivery member may track to the desired location. In yet a further aspect, the supportive rail formed by anchoring and tensioning the second delivery member prevents guide catheter back-out as the first delivery member is tracked over the second delivery member to the desired location.
In another initial guidewire tracking aspect of the method mode of the invention, the first delivery member is initially coupled to and tracked over an initial guidewire positioned within the body lumen before slideably engaging the distal end portion of the first delivery member with the distal end portion of the second delivery member and before anchoring the second delivery member""s distal end portion at the anchoring location. According to this aspect, the first delivery member is able to track distally over the initial guidewire only until the endolumenal prosthesis is positioned within the body proximally of the desired location. After the unsuccessful attempt to advance the prosthesis into the desired location over the initial guidewire, the guidewire is withdrawn from the body lumen and removed from the body. After withdrawing the initial guidewire from the body, the first delivery member is slideably engaged to the second delivery member and the second delivery member is positioned within the body lumen and anchored at the anchoring location.
In one variation of this initial guidewire tracking aspect of the method mode of the invention, the endolumenal prosthesis is able to be positioned within the body only proximally of the desired location because, while the first delivery member is advanced over the initial guidewire, the initial guidewire is prolapsed at least partially out of the body lumen. As stated above, after the unsuccessful attempt to advance the prosthesis into the desired location over the initial guidewire, the guidewire is withdrawn from the body lumen and removed from the body. After withdrawing the initial guidewire from the body, the first delivery member is slideably engaged to the second delivery member and the second delivery member is positioned within the body lumen and anchored at the anchoring location.
In another variation of the initial guidewire tracking aspect, the body lumen is a side branch which extends distally from a bifurcation region of a body lumen, the bifurcation region further comprising a second branch lumen and a bifurcation. According to this variation the initial guidewire is prolapsed out of the side branch lumen while the distal end portion of the first delivery member advances distally within the second branch lumen, rather than tracking over the initial guidewire into the side branch and to the desired location. Again, after the unsuccessful attempt to advance the prosthesis into the desired location over the initial guidewire, the guidewire is withdrawn from the body lumen and removed from the body. After withdrawing the initial guidewire from the body, the first delivery member is slideably engaged to the second delivery member and the second delivery member is positioned within the body lumen and anchored at the anchoring location.
In still another bifurcation variation for the initial guidewire tracking aspect of the method mode of the invention, prior to withdrawing and removing the initial guidewire from the body, the distal end portion of the first delivery member is confronted against the bifurcation while the first delivery member is advanced distally over the initial guidewire positioned within the side branch. Again, after the unsuccessful attempt to advance the prosthesis into the desired location over the initial guidewire, the guidewire is withdrawn from the body lumen and removed from the body. After withdrawing the initial guidewire from the body, the first delivery member is slideably engaged to the second delivery member and the second delivery member is positioned within the body lumen and anchored at the anchoring location.